Metering pump suitable for use as a fuel injector pump



lnuenior YM Attorneys 3 Sheets-Sheet 1 T. w. SCHETTLER Jan. 19, 1965 METERING PUMP SUITABLE FOR USE AS A FUEL INJECTOR PUMP Filed April 8, 1963 \\\\\w/ @N M MMWNH VMDMM WW G G Jan. 19, 1965 12w. SCHETTLER 3,166,063

METERING PUMP SUITABLE FOR USE AS A FUEL INJECTOR PUMP Filed April 8, 1963 3 Sheets-Sheet 2 Inventor Jan. 19, 1965 Filed April 8, 1963 T. W. SCHETTLER METERING PUMPSUITABLE FOR USE AS A FUEL. INJECTOR PUMP 3 Sheets-Sheet 5 I noentor Attorney;

United States Patent @fihce METERING PUW SUITABLE FUR USE AS A FUEL INJECTGR PUB H Theo Werner Schettler, Ermelo, Transvaal, Republic of South Africa, assignor to T. W. Schettler (iroprietai'y) Limited, Ermelo, Transvaal, Republic of South Airica Filed Apr. 8, 1963, Ser. No. 271,331 Claims priority, application Republic of South Africa, Apr. 16, 1962, 62/1,513 15 Claims. (Cl. 123-139) This invention relates to pumps of the kind suitable for pumping liquids in metered quantities, such as for example fuel injection pumps for internal combustion engines. I

According to the invention, a pump of the kind referred to comprises a stator and rotor assembly, the rotor having at least one port directed outwardly, an axial inlet passage connected with the or each port in the rotor, and at least one transverse bore connected to the inlet passage and having an inlet opening into it; at least one plunger member reciprocable within the bore and being biassed outwardly; a cam sleeve within the stator andconnected to it, and around the rotor and slidable co-axially with it and having at least one cam lobe on its inner periphery adapted to engage with the plunger, the cam lobe having a face which slopes relative to the sleeve axis; cam sleeve bias means for biassing the cam sleeve axially to a position in which that part of the cam lobe having the highest lift engages with the plunger member; cam sleeve position governing means for governing the position of the cam sleeve axially relative to the rotor against the action of the bias means; and drive connecting means for receiving rotary power applied to the rotor; the stator having one or more ports with which the rotor port is adapted to register during rotation of the rotor within the stator; the arrangement being such that when the rotor rotates within the stator, the plunger reciprocates within its bore under the action of the cam lobe and the bias means and thereby performs a pumping action, the rotor and stator ports being arranged to register when the plunger is on its delivery stroke.

The cam sleeve may be arcuately displaceable about its axis relative to the stator. Arcuate and axial displacement may take place simultaneously, by means of a helical slot or groove provided in the sleeve or stator and a co-operating keying element or tongue provided on the stator or sleeve, as the case may be. The sleeve is biassed conveniently to an initial axial position within the stator by means of the bias means which may be a spring, and displacement of the sleeve takes place by the cam sleeve position governing means whose displacement is conveniently proportional to variations in speed of the rotor.

The cam sleeve position governing means may comprise governor pressure pump means connected drivingly to the rotor or driven independently at a speed proportional to rotor speed, or such that its delivery pressure is proportional to rotor speed. The governor pressure pump sion with a plurality of ports in-the stator.

' ignition engine.

means may be arranged to deliver fluid under pressure a into an annular-pressure cavity defined within the stator between the cam sleeve, rotor, and stator; the cam sleeve being axially displaceable within the stator. under the ac-' .tion of fluid pressure. The pump means maybe a gear pump comprising a toothed gear wheel arranged eccenp erating member; land trically to the rotor axis, and a driving gear co-axial with the axis. If desired, a plurality of toothed gear wheels may be arranged, disposed around the gear coaxial with the axis, and eccentrically to the rotor axis, the several gear pumps so formed constituting the governor pressure pump. There may be provided delivery passages leading from the several gear pumps constituting the governor pump to the annular pressure cavity; and fluid flow control means in the various delivery passages to control the flow of fluid into the annular pressure cavity such that flow takes place into the cavity from the various pumps at various predetermined pressures.

The suction of the pumps may be fed from a reservoir provided and delivery'from the pumps may be connected to the annular pressure cavity defined between rotor, stator, and sleeve, such that increase of pressure of hydraulic fluid inside the cavity causes axial displacement of the sleeve against the action of the bias means to vary the stroke of the plunger by decreasing the throw or lift of the cam lobe relative to the plunger. The arrangement is such that the sleeve forms an annular plunger axially displaceable under the hydraulic pressure'from the pump or pumps, the pressure being proportional to the speed of the pump(s) which in turn is proportional to rotor speed. Variations in pressure may be dampened by a damper and excess pressure may be diverted by way .of a relief valve provided. V The plunger or plungers may include balls, which may be arranged to ride in cages if desired, and the bore axis may be at right angles to the rotoraxis and may intersect it. The port or ports in the stator may be connected to an injector or injectors of an internal combustion en-' gine, the delivery from the ports taking place at timed intervals depending upon'the speed of'the engine.

In-practice, the number of cam lobes and ports in the stator will be matched to the number of injectors to be fed, each port in' the stator being in connection with an injector. A plurality of ports may be used but if desired, only one port may be provided in the rotor the port being adapted .to come into register discretely in succes- The cam lobes may have varying shapes and lengths offering varying displacements and rates of displacement of the plungers. a 1

Reference 'will now be made to the accompanying drawings, which show diagrammatically two examples of the invention, as applied to the fuel pump of a compression In the drawings: FIGURE 1 shows diagrammatically a FIGURE 2a shows a detail inpart at IIII ofjthe sleeve;

FIGURE 2b shows FIGURE 3 shows diagrammatically a longitudinal se'ction of another embodiment of the invention inuone operative position;

FIGURE 4 shows atview similar to FIGURE 3 but at another longitudinal section; i V

FIGURE 5 shows an outside plan, of the cam sleeve;

FIGURE 6 shows diagrammatically an axial section bias member and an of a resilient connection between a Patented Jana. 19, 1965 a section at r b-11b ofFIGURE' shell 12 having a bore 14 within which rotor 16 is mounted The rotor 1d has to rotate co-axially with the stator.

shaft 18 whereby rotary power may be applied to it.

Cam sleeve position governing means in the form of gear pumps 29 and 22 are provided for pumping hydraulic fluid from a reservoir not shown. These pumps also act as fuel feed pumps and their operation will bemore fully described hereafter.

Thelstator is provided with radial ports 24 which are adapted toregister with the ports 26 in the rotor and are connected via passages 28, 30, and 32, to transverse bores 34 having plungers 36 biassed by. springs 38. The.

.plungers 36 are axially displaceablein the bores 34 by means of balls 49 which roll or slidejalong the inner face 42 of an annular cam ring 44 having one or more cam lobes 46, when the rotor 16 rotates within stator 12';

The cam ring 44 has a face .48 which defines an annular cavity 50 in association with rotor 16and stator 1th ,The deliveriesof'the pumps 20 and 22 are connected for discharge into cavity 50, by means of threaded connection 52. The camsleeve 44 is biassed to an initial, position .of maximum cam lobe lift by means of spring54 disposed within cavity 56 charged under pressure with fluid .(e.g. fuel-oil) whose delivery 'is'to be rnete'red-inismall discrete quantities; Inlet passages 58. are provided in rotor 16, and connect bores 34 to cavity S6, This cavity 56 is charged via threaded connection 59;.

Cam sleeve 44 is connected via helical grooves 45 and rotor axis. In this way the cam lobes 46 may beadvanced relative to the rotor 16,1-to'secure earlier operation'of the plungers 36 and consequently'earlier delivery and charging of fuel into engine cylinders.

In operation,jaliquid' such as fuel oil is charged into cavity [56 via threaded connection 59,from one of the pumps'ztl, 22 or from an independent an pump not shown and at a pressure slightly above atmospheric. Rotation of rotor 16 within statorltllcausesballs at to be cyclically displaced along bores 34 as they ride up and over cam 'lobes as. Such cyclic displacements cause 'fl16l .tobe drawn into bores 34. Inward displacement of plungers'saa' causes the inlet passages 58 to beclosed off.

and liquid in bores34 to be subjected topressure. If

'ports26 and 24 are in register thena'quantity of fuel oil will be delivered which is-proportionalto the displacement of a plunger'36 in its bore v314. 1 I

[ Ports 26. and 24. may be suitably. matched and conanengine, each" port 24 i passage 12% leading from over-pressure relief valve 88 ,of the pumps, say pump 20 to the bore.

the speed of the engine. It will also be apparent that the fuel pump may be independent as mentioned, but if desired it may form a single integral unit with the whole.

Referring now to FIGURES 3 and 4 of the drawings there is shown a fuel feed pump for an internal combustion engine. The construction is basically the same as that shown in FIGURE 1, but differs in the cam sleeve governing means, which comprises a composite. gear pump having a centrally disposed gear wheel 150 fast with the rotor 16 and four circumferentially spaced toothed gear wheels having different numbers of teeth meshing with the central gear Wheel 150. These pumps I are arranged to deliver fluid at different pressures to cavity 5t) and the manner in which they are connected to the fuel metering pump will be more fully described later.

Two of the gear pumps are designated 20 and 22. v

Inside cavity 56 there is provided an axially displace able bias member 84 against which spring 54 is arranged to abut in urging cam sleeve 44 towards the position of maximum cam lobe lift relative to the. plunger balls 40. The bias member has a co-axial stem 86 and biassing means4 for connecting it operatively to anoperating member 96; (See FIGURE 6 to be more fully described later.) a v An over-pressure relief -valve 88 is provided out. of the cavityv 5% via passage 89, and non-return inlet valves 90 are provided in the inlet-passages 58' connecting the bores 34 to the cavity 56, which is fed with pressure fluid via passage 92 from one of the gear pumps constituting the governor pressure pump. 7

Theembodimentof FIGURES 3 and 4 has a set of four bores 34 instead of two as shown in FIGURE 1.

, FIGURE 5 shows an outside planof sleeve 44 and in particular the tongue 47 for engaging with the groove whereby the sleeve is arcuately displaced about its axis when it is axially displaced.

FIGURE 6 shows'diagrammatically the resilient .con-

' nection 'between the stem 86 of the bias member 84, t

Referring again to FIGURE 3, there is shown further a control valve generally indicated by reference numeral 1% :and comprising a core 102, housed within a bore 164 in the stator, a slee ve ltio within the bore, and biasmeans in the form of a; spring 193 urging the sleeve to an initial position; A passage 116 connects the delivery of one T he core 102 has an internal passage 112 adapted to register with holes .114 provided in sleeve 1%. The holes'114leadinto an annular groove 116 around the sleeve, the groove being adapted to register with a'passage 1-18 leading into cavity 59. At-the other end of the bore there is provided a 1 into the bore 194. A'bleed passage 80 is provided out of tothevarious cylindersI Asv the engine speeds'up, so

the delivery of hydraulic pumps 20, 22 increases 'propore tionaliy to engine speed and the pressurein cavity'59 is' balanced against the pressure of spring 54 andthat ofthe fiuid in cavity 56 (cam'ring 44 in taking up abalanced another-control'valve lithe: similar to valve 160. The

cavity 5i? back to the suction ofone of the pumps.

Referring to FIGURE i4, another axial; section is shown, showinganother' valve 88a simila'rto 88, and

1 par-tsof valve 196a are numbered similarly to those of position maybe axially'and arcuately displaced relative to the stator" shell 12). The time of; delivery of the plung- V er 34' is fthereby advanced relative to the pistonsin the 7 cylinders of the engine by a determined amount and the quantity-delivered is suitably varied, depending'upon-the opening.

degreeof axial andarcuate displacement of-the cam. ring dpand depending upon thegspeed and requirements of r I the engine, The'cavityfitl 'ma y jbesprovided with a bleed It will be apparent that th elpumps 20,.22 maybe sepa 1i rately'drivenifldesired; and may'beindependent ofrotor '16,as' long astheir delivery pressure'is proportional to valve 1% but have sufiixes a. The passage a is the delivery passage of another of the pumps comprising the composite pump and is arranged to come into operation at a higher delivery pressure.

e 1 Referring to FIGURE 4 there is-shown' a non-return valve 139 in a passage 81 leading from one of -the governor pumps to the cavity 50; This valve is preloaded thus ensuring that fluid is received from this particular pump only after'a predetermined delivery' pressure has been reached by that pump, i.e. after it has reached a via passage sl, whereupon the pressure in the cavity 50 will increase and the sleeve 44 will be displaced fully against the action of the spring 54, i.e. intofa position of minimum or no cam lift and thereby cutting out the operation of the engine.

In operation of the pump as a fuel pump for an internal.

will tend to displace it towards greater cam lift and therefore greater engine'speed which would iriturn result ingreater pressure in the cavity s. As soon'as the pressure in the cavity 56'reaches a value determined by the setting of valve 88, it lifts and admits fluid 'under pressure via passage 121' into bore 164. Sleeve 106 is thereupon displaced axially against the action of spring a and 100a, depending uponrequirements; By suitable" cause the pressure incavity sew rise and will cause valves 88a and ltliia to take over,

for the next stage of operation. 7

The governor pump means therefore comprises four gear pumps, each having a pressure and capacity charac- U teristic differing from the others. The one pump delivers continually into cavity 56, two pumps deliver in stages into cavity 59 via control valves 1% andltltla and the fourth pump only delivers into'cavityl5il via valvej130 upon excess pressure due to overspeed.

If desired, the governor pump means may haveone or.

more constituent pumps delivering via valves suchasliit) adjustment, the pumps may be arranged to take over at ltistherebyplacing delivery passage 110 in connection wth cavity 50 via passage 112, holes 114, groove 116,

and passage 11%. One of the pumps will deliver at a high pressure into passage 114) and thence to cavity 50. The pressure in cavity 56 will therefore 'bebalanced against the spring 54 and the pressure in cavity 56. Fluid is bled away from cavity 50 via bleed passage 80.

Whenthe pressure in cavity 515 becomes too great valve 83 closes and shuts oi the bore 104 from cavity 56. At this stage valve 88d lifts and allows pressure fluid from cavity 55 to displace sleeve 106a and so to bring a higher pressure pump into connection with the cavity Sil, and so to take over the function of thepump previously in connection but now disconnected.

If it is required to speed up the engine then the control is operated so that-the cam sleeve 44 moves to the right;therebyincreasing the stroke of the plungers 34..

and causing more fuel to be supplied'to the engine thereby causing it to run faster. The sleeve will take up a new balanced position depending upon the spring pressure and upon the pressures in cavities 50 and 56. The p axial displacement of the cam sleeve causes it to be displaced helically about its axis relative to the stator, by

means of keying element or'tongue 47 co-operating with groove 45, thus causing the sleeve to be advanced in relation to the rotor in accordance with the requirements of the engine. The pitch of the helix will' depe'nd upon thedegree of advance required for the particular-engine with which the pump is to be used. 7 i

ment being such that whenthe rotor'rotates withinthe. f

stator, the plunger reciprocates within its bore 'under the action of the cam lobe and the plunger biasme'ans and thereby performs a pumping action, the rotor and'stator Referring now to FIGURE 7, there is shown a detail ot the relief valve $8. This valve comprises a valve closure member llfiuseated in bore 162 in stator shell 12. The member 16-6v has a passage 1% adapted to register with passage-12d in stator shell 12,'when';dis-

placed by fluid pressure incavity 56 against the. action of springifid around closure member stem 163. The;

stern 163 has a face 169 which is'arranged'to seat closably in seat 1753 provided in nut172j havinga tubular stern 174 adapted to receive a banjo connection 176 which is held sealingly inposition between gaskets 177 and 178 by nuts 1'72 and 1719. The bore of the stem 174 communicates with the banjo connection 176 via openings" 13%. Lock nut 181 provides for locking nut 172 inposition underpredetermined tension'of springififi,

In operation, closure member 166 lifts under pressure H from cavity 55 entering bore 162 by way of passage 89.

Fluid pressure from cavity 56 will then be in communica tion with here l d-i- .via passage 126. Further displacement of'rnember 169 under greater pressure will cause passage 164 to discharge into cavity 132 and'thence to a reservoir or pump suction connection via banjo connection 176. lithe pressure rises further then, facef169 seats against seat and so closes off the delivery. This will various pressures, If desired, the adjustment may be. such that there is some overlap betweenvalves of the type 88 and 88a, for the several pumps, such that the one'is already 'openingbefore the other has closed otf cornpletely.

Iclaimz. l. Apump of the transverse bore connected to the inlet-passage andlhaving an inlet :openingintoiit; "at least one plunger membep reciprocable within the bore; plunger bias means biassing' the plunger member outwardlyga cam sleevewithin the stator and connected to it, and around the rotor and slidable co-axiallywith it and having at leastoneicam lobe on its inner, periphery adapted to engage with theip'lunger, the cam lobehaving a face which slopes rclativeto the sleeve axis, and the connection betweenthe stator and "cam sleeve comprising at'least one helicalgroove and I mating element; cam sleevejbias means forbiass ing the cam lob having the highest lift engages with the plunger member; cam sleeve position governing means for governing the position of the camsleev'e axially relative to' the t stator and rotor ja'gainstathe action of theicam sl'eevebias beans; and 'driveconnecting means for receiving rotary power applied to the rotor;the statorlhavingfatxleast one 7 port with which the rotor port is adapted to register during rotation of the rotor within the stator; the. arrange ports being arranged to register when the plunger is on its delivery stroke, and the arrangement also being such that axial displacement of the'cam sleeve relative to .the stator and rotor-by the cam sleeve.position-governing means causes varcuate displacerrient of the cam sleeve aboutjitshxisrelative to the 'statorthereby providing'an' advance and retard characteristicto the cam newsman:-

tive to the rotor.

v 2. .A pump according to claim 1, "in Which-Tbackfiow cut otf means is provided for the inlet: opening into the axial inlet passage to'prevent backtlow through the inlet openingat the commencement of-a pumping stroke or the plunger member.

3. A pump according tdclaim which the backflow cut-oil meanscomprises' a non-return inlet valve;

4."A'purnp of the kind ,re'ferred to,which comprises a stator and rotor-assembly, therotor'having at least'onej' port direc'ted outwardly,v an axial inlet pass'age connected with the or each portin the rotor, and at least ,one trans- 'verse bore connected tothe inlet passage and having an inlet opening. into it; at least oneplunger member re ciprocable within the bore; bias means =biassing the f plunger memberoutwardly; a cam sleeve within ,thestator and connected to it, and around the rotor and slidable. }co-'axially with it; means defining an "annular pressure; L

cavity withinlthe' stator between' the cams'leeve, rotor, and stator, thecam sleeve having at least o'necam'zlobe on its inner periphery adapted to engage with thepluhger,

kindreferred to which comprises a stator and rotor assembly, the rotorhaving at-least one: port directed outwardly, aniaxial inlet-passage connected with-the or each portjin the rotor, and atleast one its delivery'stroke; 5. A pump according predetermined pressure valve.

and the cam lobe having a face which slopes relative to the sleeve axis; cam sleeve 'bias means for biassingthe 'ca'msleeve axially to'a position in whichthat'part of the cam lobe having the highest litt' engages with the plunger: 7 member; cam sleeve position governirigmeans for governing the position ofthe cam sleeve axially relative to the stator and rotor against the action of the cam sleeve bias" ulatin' the osition of the bias member within the stator, V D r i a the cam sleeve bias means being arranged to abut at one endagainst the bias member; cam sleeve position-governing means for governing the position of the cam sleeve axially relative to the rotor against the action of the cam sleeve bias nieansydrive connecting means for receiving I :rotary power applied tofthe rotor; the stator having one means, and comprising a governor pressure pump for o deliveringa fluid under pressure, and conduit meanscon-v nectmg thedelivery of the'pres'sure purnpto the-annular pressure cavity; drive connecting means for receiving rotary powerapplied to the rotor, the stator having one or more ports Withwhich the rotor port is adapted to" V reg sternduring rotation'of the rotor within the stator; the: V

governor pressure pump compising a gear-toothed sun wheel andaplurality of circumferentially'spaced' toothed wheelisvin mesh with the sun wheel thereby forming a pluralityfof separate'gear pumps; there beingprovided deliveryipa'ss'ages leading from the several =gear pumps arrangement being suchithat when the rotor rotateswitha in" the stator, the plunger reciprocateswithingitsxbore uns dergthef action of the cam lobe sandgthe. biasz meansxand thereby performs Lapumping @CtiOll," the rotor andsstato'r;

ports being arranged to. registerwhen the' plunger is onv the action 7 offluid" pressure. in the: afnularpressu're cavity,

I tofclaim 41in 'which thexircum: ferentially spacedf toothed 'wheels in' mesh withgthe; sun; wheelhave difi eringnumberslof;tceth:and"are arrangedf to deliverfiuid' at different pressures a t ia particularspeed. g ofjthe sun wheeljiri which fluid pressure of at jleastone of the, pumps iswarrangedito assist, the bias :means against and in which-the pressure-- frorn'the pump assisting the bias ma as; arranged to control theoperation of theff fluid flow control 'means for directing fluid pressure 'fiow 6; Apunip according" to 'climfiiin whicha plurality come into operation in stages at different :pressuresf? i s v I 7.}A pump according to claim 4 inwhrfhthe cavity; is providedwith a bleed passage. v 7 ,v S. 'A' pump accordingto clainr lyarid suitable for connection' as the fuel feed pump oflan internal combustion; engine, in which there is'provided a further pump having a delivery connectionto the cavity,,a-pressurerelief valve infthe passage and. adapt'edto be set at'a predetermined pressure corresponding.;.to a predetermined speed: of the enginejwhereby generationsof the predetermined pressure} a causes fluid to :pass through the relief valveand "into the cavity andthere is cause displacement of the sleeve tqthel cam minimum lift conditiomithei-eby preventing therspieed I l into the-annular pressure cavity orfor cutting itoff: i i

i of pumpsare arranged to oppose the bias means, but to its delivery stroke. o g 7 a 7 l0." Afpump according -;to claim 9 in which the posifor more. ports with which therotor port is-adapted to register during rotation'oi therotor Within the stator; the.

arrangement being T such thatwhen the rotor rotates within thelstator; the plunger reciprocates within its bore; f under the action of the cam lobe andthebias means and 7 thereby perforlnsa pumping action, the rotor and stator ports beingar'ranged to register when thelplu ngcr is on tioning means includes astem'projecting through a gland in the stator, and a resilient connection including second bias means *forconnecting the stem to the-fuel control of 1 an internal combustion engine, the second bias means he:

ing stiifer than the -first bias means; 7

;l1.- A pumprof the kind referred to which. comprises afstator and rotor assembly,therotorhaving at least one 1 port" directedzoutwardly, an axial'inlet passage connected with the or each portin the rotor and? at least one transversebore-connected to the. inlet passage and having an inlet opening into teat leastoneplunger member reciprog cable within the borerbias means biassing the plunger 7 member outwardly: a camsleeve within the; stator and connectedfzto it, andl-around-V'the rotor and slidablecoaxially with it and having at'least-one cam lobe on 'ritsinneriperiphery adapted; to engage with the plunger, f

the connectionbetween the stator {and cam sleeve being provided by at ;least one helical groove and mating elementg' carnisleeve biasme'ans forbiassing thezcamlsleeveaj axially; carn sleeve position-governingmeansfor govern:

7 ing' the position ofthe camsleeve axially relative to the statorand rotor against the action of the cam sleeve bias ,imeans; and drive connecting'means for receiving rotary .a power applied to therotor; the stator-having one or more' .por'ts with which'the' rotor part is adapted to register during rotation of; therotor within the stator;jthe a rrange a merit being such that when the rotor rotates within the stator,'the plunger reciprocates Within its 'bore under the action of the .cam lobe and biasmeans and thereby'per i forms a-pumping action, therotor and stator ports'be 7 ing arranged to register when the plunger member is on its delivery stroke,.and the arrangement being such that i axial displacement of' thecam' sleeve relative to the 'sta' tor and rotor: by the camsleeve position-governingmeans 1 causes farcuate, displacement of the cam'sleeveaboutits axis relativeitothe stator thereby providing an advance and retard characteristic to the cam sleeve trelat ivesto ofpthe engine-exceeding the'valuecorrespondingto'rthe 9-. A" pump of thelkind referredto which comprises co-axially with it, and having'atleast'one arn-110w on f therotor y r v t. v :7 12 Apump accordingtoclaim 11-, including means} defining an annular pressurecavity withinth'e stator'bef- "tween'the' cam fsleeve-, rotor and'stator; and in which the cam sleeve;position-governingi means comprises agover- {nor pressure pump forrdelivering a'fiuid under pressure; V and'conduit meansconnecting the delivery of the'pressilre V V pump to the pressure cavity; the governor pressure pump icomprising a gear toothed sun wheeliand a plurality of circumferentially spaced toothe'c'l' wheels in mesh 7 the-sun wheel therebyfformi'ng a plurality of separate gear pumpsythererbeing provided delivery passages leading from the several gear pumpsjconstituting the governor Qf purhp to the annular pressure cavity, and-fluid flow/ con fits inner periphery adapted toengage with the plunger; fthe cam lobe having a facefiwhich slopes relative tome sleeverairis; carnlsleeveabias means for biassingathecam sleeve;axiallytoiipositionin" which that part of the; camlobefhavingthe highest lift engages with the-plunger: 5 member; abias meniher withinthe stator iand ice-axial V with it andg axiallyslidable innit; positioninglmeans for regtrolmeans inthe various delivery passages to control th p flow or fluid into the; annular pressure 'cavity s'uch that flow takes place into the cavity from the various pumps at 5 variouspredetermined pressures; whereby the governing-j V i of the axial position oft he cam. sleeve relative to'tlie rotor can be controlled by the various fluid pressures from thegovernorpressure pump, I r

13. A pump according to claim 11, including a bias member within the stator co-axial therewith and slidable axially therein, and positioning means for regulating the position of the bias member in the stator, the cam sleeve bias means being arranged to abut at one end against the bias member.

14. A pump according to claim 11, including backflow cut-oft means for the inlet opening into the axial inlet passage to prevent backfiow through the inlet opening at the commencement of a pumping stroke of the plunger member.

15. A pump according to claim 14, in which the backflow cut-off means comprises a non'return inlet valve.

Reterences Cited by the Examiner UNITED STATES PATENTS Gordon et al. 123--139 FOREIGN PATENTS Great Britain.

RICHARD B. WILKINSON, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,166,063 January 19, 1965 Theo Werner Schettler rtified that error appears in the above numbered pat- It is hereby ce tion and that the said Letters Patent should read as ent requiring correo corrected below.

Column 6, line 35, after "the" insert cam sleeve axially to a position in which that part of-the line 36, for "lob" read H lobe same column 6, line 40, for "beans" read means column 7, line 21, after "fluid" insert flow line 55, for "is" read to Signed and sealed this 13th day of July 1965.

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents ERNEST W. SWIDER Attesting Officer 

1. A PUMP OF THE KIND REFERRED TO WHICH COMPRISES A STATOR AND ROTOR ASSEMBLY, THE ROTOR HAVING A LEAST ONE PORT DIRECTED OUTWARDLY, AN AXIAL INLET PASSAGE CONNECTED WITH THE OR EACH PORT IN THE ROTOR, AND AT LEAST ONE TRANSVERSE BORE CONNECTED TO THE INLET PASSAGE AND HAVING AN INLET OPENING INTO IT; AT LEAST ONE PLUNGER MEMBER RECIPROCABLE WITHIN THE BORE; PLUNGER BIAS MEANS BIASSING THE PLUNGER MEMBER OUTWARDLY; A CAM SLEEVE WITHIN THE STATOR AND CONNECTED TO IT, AND AROUND THE ROTOR AND SLIDABLE CO-AXIALLY WITH IT AND HAVING AT LEAST ONE CAM LOBE ON ITS INNER PERIPHERY ADAPTED TO ENGAGE WITH THE PLUNGER, THE CAM LOBE HAVING A FACAE WITH SLOPES RELATIVE TO THE SLEEVE AXIS, AND THE CONENCTION BETWEEN THE STATOR AND CAM SLEEVE COMPRISING AT LEAST ONE HELICAL GROOVE AND MATING ELEMENT; CAM SLEEVE BIAS MEANS FOR BIASSING THE CAM LOB HAVING THE HIGHEST LIFT ENGAGES WITH THE PLUNGER MEMBER; CAM SLEEVE POSITION GOVERNING MEANS FOR GOVERNING THE POSITION OF THE CAM SLEEVE AXIALLY RELATIVE TO THE STATOR AND ROTOR AGAINST THE ACTION OF THE CAM SLEEVE BIAS BEANS; AND DRIVE CONNECTING MEANS FOR RECEIVING ROTARY POWER APPLIED TO THE ROTOR; THE STATOR HAVING AT LEAST ONE PORT WITH WHICH THE ROTOR PORT IS ADAPTED TO REGISTER DURING ROTATION OF THE ROTOR WITHIN THE STATOR; THE ARRANGEMENT BEING SUCH THAT WHEN THE ROTOR ROTATES WITHIN THE STATOR, THE PLUNGER RECIPROCATES WITHIN ITS BORE UNDER THE ACTION OF THE CAM LOBE AND THE PLUNGER BIAS MEANS AND THEREBY PERFORMS A PUMPING ACTION, THE ROTOR AND STATOR PORTS BEING ARRANGED TO REGISTER WHEN THE PLUNGER IS ON ITS DELIVERY STROKE, AND THE ARRANGEMENT ALSO BEING SUCH THAT AXIAL DISPLACEMENT OF THE CAM SLEEVE POSITION-GOVERNING STATOR AND ROTOR BY THE CAM SLEEVE POSITION-GOVERNING MEANS CAUSES ARCUATE DISPLACEMENT OF THE CAM SLEEVE ABOUT ITS AXIS RELATIVE TO THE STATOR THEREBY PROVIDING AN ADVANCE AND RETARD CHARACTERISTIC TO THE CAM SLEEVE RELATIVE TO THE ROTOR. 